The purpose of the flight was to conduct two cross-country instrument flight rules practice flights between two airports. After departure, the pilot reported that he entered instrument meteorological conditions (IMC) shortly after takeoff and remained in IMC until he was near his destination airport. The pilot stated that he “messed up” his first approach, and he performed a missed approach. After maneuvering for his second approach, the pilot established the airplane for his second attempt; however, the pilot reported that he was “task-saturated” and that he “neglected to lower the landing gear.” While continuing the approach, the pilot described that he developed “tunnel vision” and did not verify that the landing gear was down. The pilot subsequently landed the airplane on the runway with the landing gear still retracted resulting in substantial damage to the fuselage. The pilot reported there were no preaccident mechanical malfunctions or failures that would have precluded normal operation. Postaccident examination of the airplane confirmed that the landing gear position handle was in the up position and that the landing gear operated normally when extended. The landing gear position warning horn was not functional.